The present invention generally relates to an integrated active module for use in radio frequency (RF) systems and, more particularly to an integrated active module that can include an assembly having a wide-band balun, amplifiers and micro-electro-mechanical systems (MEMS) switches arranged with a radiator so as to couple RF energy from a transmitter and/or to a receiver.
A wide variety of antennas are used to transmit and/or receive signals (e.g., RF signals) at microwave and/or millimeterwave frequencies. Often, the antennas are formed from a plurality of radiators. Each radiator can be associated with a transmitter used to generate signals to be transmitted by the antenna and a receiver used to process signals received by the antenna. Many transmit/receive (TR) modules are provided with an amplifier for the transmit path and an amplifier for the receive path.
The TR module can include switches that are used to select which of the transmitter or the receiver is coupled to the radiator. In the past, the switches have been implemented with PIN diodes, gallium arsenide (GaAs) field effect transistors (FETs), latching circulators and electromechanical devices such as relays.
Circuit loss is an inherent problem in RF transceiver circuits that can degrade system performance. Contributing factors to circuit loss include, for example, conductor loss, dielectric material loss and so forth. Prior attempts to compensate for circuit loss and improve system performance have included providing additional signal gain with the TR module amplifiers. However, providing additional gain in the TR module amplifiers can result in increasing the size and power consumption of the TR module. In addition, heat dissipation problems can arise when higher gain amplifiers are employed.
Location of the TR module with respect to the radiator is also a concern since loss will increase with increased length of the conductors coupling the TR module and the radiator. The size of the TR module components contribute to the placement of the TR module. That is, the larger the TR module, the further the TR module may have to be placed from the radiator to accommodate each TR module for a multiple radiator antenna.
Accordingly, there exists a need in the art for higher performance integrated radiator/TR modules with compact size for use in RF applications.
According to one aspect of the invention, the invention is directed to an integrated module for an active antenna radiator assembly, the integrated module switchable between a receive mode and a transmit mode. The integrated module can include a first amplifier to amplify signals to be transmitted by the radiator, a second amplifier to amplify signals received by the radiator, a dual input wideband balun, a transmit line coupled to an output of the first amplifier and the balun, a receive line coupled to an input of the second amplifier and the balun, a first MEMS switch to shunt the receive line to ground when the integrated module is placed in the transmit mode and a second MEMS switch to shunt the transmit line to ground when the integrated module is placed in the receive mode.
According to another aspect of the invention, the invention is directed to an active antenna radiator assembly. The assembly can include a radiator and an integrated module disposed behind the radiator and switchable between a receive mode and a transmit mode. The integrated module can include a high power amplifier (HPA) for amplifying signals to be transmitted by the radiator; a low noise amplifier (LNA) for amplifying signals received by the radiator; a wideband balun having at least a first arm and a second arm, the arms respectively coupled to the radiator via a pair of probes that are 180 degrees out of phase with respect to the radiator; a receive line coupled to an input of the LNA and the balun; a transmit line coupled to an output of the HPA and the balun; a receive micro electro-mechanical system (MEMS) switch to selectively couple the receive line to ground when the integrated module is placed in the transmit mode; and a transmit MEMS switch to selectively couple the transmit line to ground when the integrated module is placed in the receive mode.